Karbeka, M. et al. 2026. MICROSTRUCTURAL CHARACTERIZATION OF BIOCHAR–CHITOSAN COMPOSITES LOADED WITH NITROGEN AND Fe FOR SLOW-RELEASE FERTILIZER APPLICATIONS. Walisongo Journal of Chemistry. 9, 1 (Jul. 2026), 67–75. DOI:https://doi.org/10.21580/wjc.v9i1.31598.